ESTRO 35 Abstract-book

ESTRO 35 2016 S311

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PO-0666

Comparing the efficacy of low-dose radiotherapy in

patients with aggressive and indolent lymphomas

C. Furlan

Centro di Riferimento Oncologico, Radiation Oncology,

Aviano, Italy

, P. Bulian

, M. Michieli

, M. Spina

, A. Ermacora

M. Trovo

, U. Tirelli

, G. Franchin

Centro di Riferimento Oncologico, Hematology, Aviano, Italy

Centro di Riferimento Oncologico, Medical Oncology,

Aviano, Italy

Azienda Ospedaliera Santa Maria degli Angeli, Hematology,

Pordenone, Italy

Purpose or Objective:

Low-dose radiotherapy (LDRT) is a

highly effective treatment in indolent non-Hodgkin

lymphomas (NHLs). However, a reduced efficacy in aggressive

lymphomas has never been demonstrated. We aimed to

assess the effect of histologic type on disease response to

LDRT.

Material and Methods:

Data from a clinical phase-II trial

using LDRT for palliation in diffuse large B-cell lymphoma

(DLBCL) patients were compared with clinical outcome of

patients with follicular lymphoma (FL), marginal zone

lymphoma (MZ), and mycosis fungoides (MF) which were

treated with LDRT at our Institution in the same period. LDRT

consisted of 4 Gy in 2 fractions on symptomatic areas only for

both DLBCL and indolent NHLs. Bulky disease was defined as

> 5 cm in maximum diameter. Chemoresistance was defined

as the failure of chemo to achieve a complete or partial

response, or as disease relapse after a complete response.

Clinical response was assessed 21 days after LDRT, and was

defined as reduction > 50% of maximum diameter of the

radiated lesions. Response evaluation was performed with

CT-scan or clinical exam for palpable lesion. Toxicity was

scored using the CTCAE v3.0.

Results:

In all, 35 patients were evaluated. Sixteen were

male; histologies were 17 DLBCL, 8 FL, 6 MZ, and 4 MF.

Characteristics were generally balanced between the two

groups. However, DLBCL patients were more likely to have

bulky disease and chemoresistance. Median follow up was 7

months (range, 1 – 49 months). No significative difference

was noted concerning overall response rate between DLBCL

and indolent NHLs (overall response rate was 70% (12/17) and

83% (15/18) for patients with aggressive and indolent forms,

respectively; p = 0.39), but indolent forms were associated

with a higher rate of complete response (complete response

rate was 61% (11/18) and 35% (6/17) for patients with

indolent and aggressive NHL, respectively; p = 0.09). Only 1

case of toxicity was noted (grade 2 nausea). The median

duration of response was 7 months (range, 1 – 35 months).

Among responders, only 2 patients progressed within the

radiated field at the time of last follow-up visit.

Conclusion:

Efficacy of LDRT for DLBCL and indolent NHL

patients resulted comparable in terms of overall response

rate. Complete response rate was higher in the indolent NHL

population than in the subset of DLBCL patients included in

the phase II trial.

PO-0667

Second malignancies after TBI in AHCT for relapsed

follicular lymphoma

S. Tisseverasinghe

, R. Samant

, M. Sabloff

, Y. Xu

, C.

Bredeson

, L. Huebsch

, P. Genest

, P. Cross

University of Ottawa and The Ottawa Hospital, Radiation

Oncology, Ottawa, Canada

University of Ottawa and The Ottawa Hospital,

Haematology, Ottawa, Canada

Ottawa Hospital Research Institute, Epidemiology, Ottawa,

Canada

Purpose or Objective:

Follicular lymphoma (FL) is an

indolent disease with a progressive relapsing course.

Autologous hematopoietic cell transplantation (AHCT) has

been proven to be effective in treating recurrences. At The

Ottawa Hospital (TOH), AHCT utilizing total body irradiation

(TBI) has been used to treat FL patients, who have progressed

after at least one course of chemotherapy, for over 20 years.

There are concerns in the literature regarding the use of TBI

due to the potential for radiation-induced second

malignancies. However, we hypothesize that TBI based

conditioning regimens should not lead to excessive second

cancers. We undertook a review of our large single-institution

AHCT experience in order to assess patient outcomes and

rates of second malignancy.

Material and Methods:

We retrospectively reviewed

consecutive patients undergoing AHCT for relapsed FL from

July 1991 to February 2013. All patients received treatment

at TOH, a regional tertiary center. The most common pre-

AHCT conditioning regimen was Etoposide 60 mg/kg /

Melphalan 140 mg/m2 / TBI. Patients received TBI on a linear

accelerator using high energy photons (10MV or 18MV) and

utilizing a translating bed technique. 92% received 5 Gy /

1fraction / 1day, the rest received 12 Gy / 6 fractions / 3

days. Lung attenuators were used for all patients to maintain

a homogeneous dose. Patient information was stored in our

bone marrow transplant registry database. This includes

baseline characteristics, demographics, outcomes, types and

dates of second cancers. Descriptive statistics were

calculated for all relevant demographic variables. Overall

survival of the cohort was estimated using the Kaplan-Meier

method. Cumulative incidence of second malignancy was

calculated; death was a competing risk.

Results:

Overall, we evaluated 174 patients with a median

age of 50 years at transplant. There were 106 men and 68

women included, and median follow-up was 6.0 years after

AHCT. Overall survival at 1, 5, 10 and 15 years was 93%, 73%,

57% and 47% respectively. The median follow-up among

survivors was 8.3 years. Eighteen of 174 patients (10.3 %)

developed a second malignancy. Of these, 11 (6.3%) had solid

tumors, 2 (1.1%) had AML and 5 (2.9%) developed

myelodysplastic syndrome. Median time to second malignancy

was 7.2 years, with cumulative incidences of developing

second cancer at approximately 4.5% and 8.2% at 5 and 10

years. Solid tumors included breast (2), prostate (3),

endometrial (1), skin (4) and lung cancers (1). Furthermore,

82% of patients who developed solid tumors were alive at last

follow-up.

Conclusion:

Our results with AHCT utilizing TBI in the

management of relapsed FL patients have been very good.

Indeed, most patients survive more than 10 years after

treatment. The risk of second cancers is acceptable and

compares favorably with the published literature. Moreover,

we suspect screening, particularly for solid tumors post-

treatment, may help detect early treatable second

malignancies.

PO-0668

Outcome of low and intermediate dose radiotherapy in

head and neck MALT lymphoma

F. Rahman

Guy's and St Thomas' NHS Foundation Trust and King's Health

Partners Academic Health Sciences Centre, Department of

Clinical Oncology, London, United Kingdom

, J. Brady

, S. Galli

, N.G. Mikhaeel

Purpose or Objective:

Mucosa-associated lymphoid tissue

(MALT) lymphoma can present in several sites in the head and

neck and is often treated with radiotherapy. MALT lymphoma

of the salivary and lacrimal glands is >300 fold more common

in patients with Sjogren’s syndrome (SS) than in the rest of

the population and tends to be a multifocal process. The

optimal dose of radiotherapy is not established. The aim of

this study is to analyse the outcome of radiotherapy for head

and neck MALT lymphoma in patients with and without SS.

Material and Methods:

A retrospective review of

departmental records identified 26 patients with head & neck

MALT lymphoma treated with radiotherapy between 2003-

2013. Inclusion criteria were histologically proven MALT

lymphoma and complete radiotherapy record. The primary

end-points were objective response rate and response